Select the correct answer from the choice in bracket to complete each sentence:-
An element Z with zero valency is a — [metal/noble gas/non-metal].

Select the correct answer from the choice in bracket to complete each sentence:- An element 'X' has six electrons in its outer or valence shell. Its valency is _________ [+2/-2/-1].

Select the correct answer from the choice in bracket to complete each sentence: A foul smelling gas formed when hydrogen reacts with a molten non-metal, is _______[hydrogen chloride, hydrogen sulpide, ammonia].

Select the correct answer from the choice in bracket to complete each sentence:- An element 'Y' has electronic configuration 2, 8, 6. The element 'Y' is a _________ [metal/non-metal/noble gas].

Select the correct answer from the choice in bracket to complete each sentence: The reactive element from the two monoatomic elements is _______ [neon/silicon].

Select the correct answer from the choice in bracket to complete each sentence:- Magnesium atom with electronic configuration 2, 8, 2 achieves stable electronic configuration by losing two electrons, thereby achieving stable electronic configuration of the nearest noble gas _________ [neon/argon).

Select the correct answer from the choice in bracket to complete each sentence: An example of a monoatomic molecule is _______ [hydrogen/helium).

Select the correct answer from the choice in bracket to complete each sentence. Matter is added or removed during a - [chemical/physical] change

Select the correct answer from the choice in bracket to complete each sentence. Energy required for completion of a physical change is - [released/absorbed] when the change is reversed.

Select the correct answer from the choice in bracket to complete each sentence. A change in which a substance retains its identity is a — [physical/chemical] change

Select the correct answer from the choice in bracket to complete each sentence: A soluble solid is separated from an insoluble solid by ________ [fractional crystallisation/ solvent extraction]